Crews Fulton, Nixon Kimberly, Kim Daniel, Joseph James, Shukitt-Hale Barbara, Qin Liya, Zou Jian
Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, CB 7178, Chapel Hill, NC 27599, USA.
Alcohol Clin Exp Res. 2006 Nov;30(11):1938-49. doi: 10.1111/j.1530-0277.2006.00239.x.
Binge ethanol administration causes corticolimbic brain damage that models alcoholic neurodegeneration. The mechanism of binge ethanol-induced degeneration is unknown, but is not simple glutamate-N-methyl-D-aspartate (NMDA) excitotoxicity. To test the hypothesis that oxidative stress and inflammation are mechanisms of binge ethanol-induced brain damage, we administered 4 antioxidants, e.g., butylated hydroxytoluene (BHT), ebselen (Eb), vitamin E (VE), and blueberry (BB) extract, during binge ethanol treatment and assessed various measures of neurodegeneration.
Adult Sprague-Dawley rats were treated with intragastric ethanol 3 times per day (8-12 g/kg/d) alone or in combination with antioxidants or isocaloric diet for 4 days. Animals were killed, and brains were perfused and extracted for histochemical silver stain determination of brain damage, markers of neurogenesis, or other immunohistochemistry. Some animals were used for determination of nuclear factor kappa B (NF-kappaB)-DNA binding by electrophoretic mobility shift assay (EMSA) or for reverse transcription-polymerase chain reaction (RT-PCR) of cyclooxygenase 2 (COX2).
Binge ethanol induced corticolimbic brain damage and reduced neurogenesis. Treatment with BHT reversed binge induced brain damage and blocked ethanol inhibition of neurogenesis in all regions studied. Interestingly, the other antioxidants studied, e.g., Eb, VE, and BB, did not protect against binge-induced brain damage. Binge ethanol treatment also caused microglia activation, increased NF-kappaB-DNA binding and COX2 expression. Butylated hydroxytoluene reduced binge-induced NF-kappaB-DNA binding and COX2 expression.
Binge-induced brain damage and activation of NF-kappaB-DNA binding are blocked by BHT. These studies support a neuroinflammatory mechanism of binge ethanol-induced brain damage.
暴饮乙醇会导致皮质边缘脑区损伤，可模拟酒精性神经退行性变。暴饮乙醇诱导神经退行性变的机制尚不清楚，但并非简单的谷氨酸-N-甲基-D-天冬氨酸（NMDA）兴奋性毒性。为了验证氧化应激和炎症是暴饮乙醇诱导脑损伤的机制这一假说，我们在暴饮乙醇治疗期间给予4种抗氧化剂，即丁基化羟基甲苯（BHT）、依布硒啉（Eb）、维生素E（VE）和蓝莓（BB）提取物，并评估了神经退行性变的各项指标。
成年Sprague-Dawley大鼠每天经胃内给予乙醇3次（8-12克/千克/天），单独给药或与抗氧化剂或等热量饮食联合给药，持续4天。处死动物，灌注并提取大脑，用于组织化学银染以确定脑损伤、神经发生标志物或其他免疫组织化学分析。部分动物用于通过电泳迁移率变动分析（EMSA）测定核因子κB（NF-κB）-DNA结合情况，或用于环氧合酶2（COX2）的逆转录-聚合酶链反应（RT-PCR）。
暴饮乙醇诱导皮质边缘脑区损伤并减少神经发生。BHT治疗可逆转暴饮诱导的脑损伤，并在所有研究区域阻断乙醇对神经发生的抑制作用。有趣的是，所研究的其他抗氧化剂，如Eb、VE和BB，并不能预防暴饮诱导的脑损伤。暴饮乙醇治疗还导致小胶质细胞活化，增加NF-κB-DNA结合和COX2表达。丁基化羟基甲苯可减少暴饮诱导的NF-κB-DNA结合和COX2表达。
BHT可阻断暴饮诱导的脑损伤和NF-κB-DNA结合的激活。这些研究支持暴饮乙醇诱导脑损伤的神经炎症机制。
